From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Thu, 8 Oct 2020 00:00:25 -0400
Subject: [PATCH] Fix "Not a string" Map Conversion spam

The maps did convert successfully, but had noisy logs due to Spigot
implementing this logic incorrectly.

This stops the spam by converting the old format to new before
requesting the world.

Track spigot issue to see when fixed: https://hub.spigotmc.org/jira/browse/SPIGOT-6181

diff --git a/src/main/java/net/minecraft/world/level/saveddata/maps/MapItemSavedData.java b/src/main/java/net/minecraft/world/level/saveddata/maps/MapItemSavedData.java
index d6ed799716f13cb3f72e66f9d57c6ec90c1eb272..7a6fbd4be33e93c7f09b1ed146ae25fe6c6b503c 100644
--- a/src/main/java/net/minecraft/world/level/saveddata/maps/MapItemSavedData.java
+++ b/src/main/java/net/minecraft/world/level/saveddata/maps/MapItemSavedData.java
@@ -15,6 +15,8 @@ import net.minecraft.core.BlockPos;
 import net.minecraft.nbt.CompoundTag;
 import net.minecraft.nbt.ListTag;
 import net.minecraft.nbt.NbtOps;
+import net.minecraft.nbt.NumericTag;
+import net.minecraft.nbt.StringTag;
 import net.minecraft.nbt.Tag;
 import net.minecraft.network.chat.Component;
 import net.minecraft.network.protocol.Packet;
@@ -103,7 +105,26 @@ public class MapItemSavedData extends SavedData {
     }
 
     public static MapItemSavedData load(CompoundTag nbt) {
-        DataResult<ResourceKey<Level>> dataresult = DimensionType.parseLegacy(new Dynamic(NbtOps.INSTANCE, nbt.get("dimension"))); // CraftBukkit - decompile error
+        // Paper start - fix "Not a string" spam
+        Tag dimension = nbt.get("dimension");
+        if (dimension instanceof NumericTag && ((NumericTag) dimension).getAsInt() >= CraftWorld.CUSTOM_DIMENSION_OFFSET) {
+            long least = nbt.getLong("UUIDLeast");
+            long most = nbt.getLong("UUIDMost");
+
+            if (least != 0L && most != 0L) {
+                UUID uuid = new UUID(most, least);
+                CraftWorld world = (CraftWorld) Bukkit.getWorld(uuid);
+                if (world != null) {
+                    dimension = StringTag.valueOf("minecraft:" + world.getName().toLowerCase(java.util.Locale.ENGLISH));
+                } else {
+                    dimension = StringTag.valueOf("bukkit:_invalidworld_");
+                }
+            } else {
+                dimension = StringTag.valueOf("bukkit:_invalidworld_");
+            }
+        }
+        DataResult<ResourceKey<Level>> dataresult = DimensionType.parseLegacy(new Dynamic(NbtOps.INSTANCE, dimension)); // CraftBukkit - decompile error
+        // Paper end - fix "Not a string" spam
         Logger logger = MapItemSavedData.LOGGER;
 
         Objects.requireNonNull(logger);